This invention relates to a cover system for an open compartment. In particular, the invention relates to a cover system suitable for covering the open box, or cargo compartment, of a pick-up truck.
It is known in the art to provide a cover made of a flexible material and adapted to cover the box of a pick-up truck or the like, to protect the contents thereof from the elements. Such a cover can be made of fabric, flexible plastic, or other sheet material. The cover is commonly secured to a metal frame on the edge of the box with a method of reversible attachment. Because pick-up trucks typically are used and stored outdoors, the fabric and the means of attachment of the fabric to the frame are exposed to the elements which can include heavy moisture and extreme heat and cold, as well as dust, mud, rocks and other materials transported in the box.
The exposure to the elements creates problems for the covering and the structure used to reversibly attach the cover to the frame. Efforts to use convenient structures for attaching the cover to the metal structure tend to be subject to exposure to the elements and wear from repetitive use of the attachment means under those conditions. Moreover, exposure to heat and cold cause the covering to expand and contract, making the cover either loose and wrinkled in appearance, or making it difficult to secure the covering in the closed position.
A prior art attachment design for convenient reversible attachment of the covering to the frame uses a hook and loop fastening system sold under the trademark VELCRO(copyright). In this system, strips of hook-bearing material are adhesively attached to a metal frame secured to the upper edges of the side of the truck box. Strips of loop-bearing material are permanently affixed to the downwardly facing surface of the cover material at its side edges opposite the metal frame. When the cover material is aligned over the truck box, and the strips of loop-bearing material on the downwardly facing side edges of the cover are pressed into contact with the strips of hook-bearing material adhesively fixed to the outer walls of the frame, such that a reversible yet secure mating is obtained. Although this system works well when first installed, it suffers from deterioration over time due to the repetitive pulling on the VELCRO(copyright) material attached to the frame in a direction away from the frame, particularly because it also is exposed to the elements. Specifically, the adhesive that attaches the hook-bearing strips to the frame will deteriorate over time because of the pulling motion which occurs when the cover is detached from the frame, and because of exposure to sun, moisture, and extreme temperature fluctuations. Moreover, heat or cold can cause the length and width dimensions of the cover and the frame to expand and contract, causing stresses in the adhesive bond of the VELCRO(copyright) material to the frame even when the cover is secured over the box.
It is another object of the invention to provide an adjustment system for a pick-up truck box covering so that the cover material will remain taut over the truck box in changing weather conditions.
It is a further object of the invention to provide an adjustment system for a pick-up truck box covering so that the cover material will not become overly stretched or too short or narrow as a result of changing weather conditions.
In one inventive aspect of the disclosed subject matter, a cover system for a truck box or open top container is provided comprising a flexible cover material of approximately the same dimensions as the opening of the truck box or container, the flexible cover material having first fastening means in the form of strips of loop-bearing material fixedly attached at its sides, side rails capable of being mounted generally along the upper edges of the side walls of the truck box, each said side rail having an outwardly facing surface defining a channel portion, and second fastening means being in the form of substantially rigid strip members having strips of hook-bearing material bonded thereto, said substantially rigid strip members being receivable in laterally sliding engagement in said channel portions of said side rails, and obstructed from sliding out.
The foregoing system eliminates the adhesive mounting of the second fastening means directly to the frame at the edge of the truck box, as in prior art systems. By eliminating the adhesive holding one portion of the hook and loop fasteners to the frame, the instant invention eliminates wear problems associated with the repeated force of separating the hook portion from the loop portion of the connectors, and with poor initial and long term adhesion and weathering.
Another inventive feature of the disclosed cover system for an open top container or truck box comprises a flexible cover of approximately the same dimensions as the container or truck box, said flexible cover having a front edge and a rear edge, said front edge of said flexible cover being affixed to a front header apparatus, said front header apparatus spanning the width of said truck box or open top container and being adjustably mounted at the front end thereof, said rear edge of said flexible cover being permanently affixed to a rear header apparatus, said rear header apparatus spanning the width of said truck box or open top container and capable of being releasably secured to said rear end thereof, and an adjustable tension control assembly that provides a forwardly biased force against said front header apparatus to urge said front header toward the front of the truck box or open container so as to maintain said flexible cover material in a taut condition, or to relieve stress due to contraction of the cover.
In one embodiment, the side rails are in the form of aluminum extrusions that provide channel portions to receive said second fastening means and support members for supporting said front header apparatus, said rear header apparatus, and said tension control assembly.